Why the World Cup soccer ball looks so different

Why does the World Cup ball look so different year after year? It's a question we posed to John Eric Goff — a physics professor at University of Lynchburg and author of "Gold Medal Physics: The Science of Sports." Turns out, some of those changes haven't been for the best. And have caused more problems than they solved. The following is a transcript of the video.

The typical soccer ball looks like this. Black and white with a bunch of these panels. But that's not what the World Cup balls look like. So, what's going on?

First things first, you want a soccer ball to be as spherical as possible.

John Eric Goff: "In the old days, we had balls that had the bucky ball shape, the Epcot Center shape, 20 hexagons, the 12 pentagons. And that was a very good approximation to a sphere. But starting in 2006 with the World Cup in Germany...there were more creative ways to make a sphere."

New technology enables Adidas to start designing the balls with fewer panels. Which created a serious problem. Because fewer panels means fewer seams. And, more importantly, a smoother surface.

John Eric Goff: "If the ball gets too smooth, the air resistance goes up. It's like kicking a beach ball."

And that's exactly what happened with the 2006 Teamgeist ball. Players complained the ball didn't go where they expected it to. So, in 2010, Adidas compensated by adding some texture to roughen up the surface. Problem solved, right?

John Eric Goff: "Jabulani was a spectacular failure because it was not rough enough. When the ball would be kicked at certain speeds, you'd notice it would slow down dramatically part way through the flight."

And the panels kept disappearing. The 2014 ball had the fewest panels yet. But this time Adidas compensated.

John Eric Goff: "Despite having two fewer panels, the total seam length around the ball was 68% longer than Jabulani."

So, at least, the ball had the right amount of roughness this time and flew farther than the 2010 ball. As for 2018:

John Eric Goff: "The total seam length is actually 30% longer than the Brazuca! So now you run the risk of the ball being a little too rough."

Adidas compensated for this by also making the seems shallower. And a study that Goff led showed that the Telstar 18 performs similarly to Brazuca. But it still has a bit more drag, and might not travel as far on high-speed kicks.

Regardless, all of this begs the question: If the goal is to produce a ball that's similar to what athletes practice with for years, then why does the World Cup ball keep changing? Turns out, it's not about the players or the game at all.

John Eric Goff: "There's a new ball released for every World Cup and I think the primary reason is money."

The 2018 World Cup ball costs over $100.

John Eric Goff: "And these balls fly off the shelves!"

That's a pretty big investment, considering you can get a regular ball for under $20. To be fair:

John Eric Goff: "The technologies used to make these balls is much much greater than what we used as kids. The panels on these balls are thermally bonded, it helps keep the water out of the inside of the ball, keep the ball from getting waterlogged and making it heavier."